I believe it was this one: https://www.atacamadesertstargazing.com

However, it was a decade ago and I can't find any receipts. I remember they also had a couple condos you could rent on the property, but I don't see any mention on their website. Might have moved them to Airbnb, or moved exclusively to offering star tours.

Or I have the totally wrong link!

EDIT Actually!! It was this place. https://www.spaceobs.com/en/Services/Star-Tours

The site seems old and I can’t tell if they’re still actually in business. However, that’s definitely the tour. They also still have links to the place you can stay on-site, which I very much recommend if it’s still a thing: https://www.spaceobs.com/en/Atacama-Lodge